Ancient humans migrated out of Africa to escape a drying climate, says a new study—a finding that contradicts previous suggestions that ancient people were able to leave because a then-wet climate allowed them to cross the generally arid Horn of Africa and Middle East.
East Africa’s rift valley is considered by many to be the cradle of humanity. In the Turkana region of northwest Kenya, researchers Christopher Lepre and Tanzhuo Liu of Columbia University’s Lamont-Doherty Earth Observatory are cooperating with colleagues to study questions of human evolution, from the creation of the earliest stone tools to climate swings that have affected developing civilizations.
Who were our earliest ancestors? How and when did they evolve into modern humans? And how do we define “human,” anyway? Scientists are exploring Kenya’s Lake Turkana basin to help answer these questions.
Because of climate change, spring, summer, fall and winter in the temperate zones are all arriving on average 1.7 days earlier than they ever have before. The changing climate with its more extreme weather is affecting many plant and animal species, disturbing their habitat and disrupting ecosystem functioning. How will plants and animals deal with these challenges?
Life arose from the sea, so they say,
And Earth’s family tree is still branching today.
Our view of the old structure way down below:
Mysterious, shrouded, a faded tableau.
An ancient island’s trove of treasure: Madagascan fauna
Tenrec, fossa, lemur, hippo, dugong, bat, iguana.
A giant bird – O, wondrous beast! – a half a ton, and tall,
Laid foot-long eggs, had beefy legs, and did not fly at all.
On a high ridge in Arizona’s Petrified Forest National Park, paleontologist Paul Olsen sits on the fallen trunk of a 215-million-year-old tree, now turned to stone. The tree once loomed 70 or 80 feet above a riverine landscape teeming with fish, turtles, giant crocodilians and tiny, early species of dinosaurs.
In Arizona’s Petrified Forest National Park, researchers are scouring the fossil-rich surface and drilling deep into ancient rocks to learn what happened during the late Triassic, some 201 million to 235 million years ago.
The creation of the narrow isthmus that joins North and South America changed not just the world map, but the circulation of oceans, the course of biologic evolution, and probably global climate. Scientists try to decipher the story behind its formation.
The formation of the slender land bridge that joins South America and North America was a pivotal event in earth’s history. At its narrowest along the isthmus of Panama, it changed not just the world map, but the circulation of oceans, the course of biologic evolution, and global climate. Cornelia Class, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory, and Esteban Gazel, a Lamont adjunct researcher now based at Virginia Tech, are looking into a key factor: the Galápagos Plume.